Rubber composition for tire

摘要

The present technology provides a rubber composition for a tire which improves the low rolling resistance, dry performance, wet performance, and workability so as to surpass conventional levels. In the rubber composition for a tire according to the present technology, silica is blended into the composition in an amount of 90 to 150 parts by mass relative to 100 parts by mass of a diene rubber containing at least 25 mass % of a modified conjugated diene polymer rubber having a siloxane structure in at least some of the terminal-modifying groups. A silane coupling agent is blended into the composition in an amount of 3 to 20 mass % relative to the amount of silica, and an alkyltriethoxysilane having an alkyl group with 7 to 20 carbons is blended in an amount of 0.1 to 20 mass % relative to the amount of silica.

主权项

1. A rubber composition for a tire, the rubber composition comprising: silica being blended in an amount of 90 to 150 parts by weight per 100 parts by weight of a diene rubber containing at least 25 wt. % of a modified conjugated diene polymer rubber (a) having a siloxane structure in at least some terminal-modifying groups, and from 40 to 75 wt. % of a terminal-modified conjugated diene polymer rubber (b) being a terminal-modified conjugated diene polymer rubber other than the modified conjugated diene polymer rubber (a) and having a functional group with reactivity to silanol groups;
a silane coupling agent being blended in an amount of 3 to 20 wt. % relative to the amount of silica; and an alkyltriethoxysilane having an alkyl group with 7 to 20 carbons, and being blended in an amount of 0.1 to 20 wt. % relative to the amount of silica; the modified conjugated diene polymer rubber (a) having a weight average molecular weight (Mw) of 600,000 to 1,000,000; and the terminal-modified conjugated diene polymer rubber (b) having an aromatic vinyl unit content of 25 to 40 wt. %, a vinyl unit content of 36 to 65 wt. %, a glass transition temperature of −40 to −22° C., a weight average molecular weight (Mw) of 900,000 to 1,400,000, and a ratio (Mw/Mn) of the weight average molecular weight (Mw) and a number average molecular weight (Mn) of at least 2.3.